Is the back and leg pain a herniated disc compressing a nerve? If it is a herniated disc compressing the nerve, then how to explain the following situations: 1. Patients who have undergone CT or MRI examination within six months after disc herniation surgery and found no change in the site of herniation. Tong Guohai, Department of Radiology, Shanghai Ruijin Hospital 2. Why patients with bulging discs can also have the same symptoms of back and leg pain as patients with herniated discs. 3. Through our CT-guided drug treatment, the patient’s back and leg pain can disappear, but the herniation does not change on CT and MRI examination. 4, Some normal people do not have symptoms of low back and leg pain, but have herniated discs on CT and other imaging.